An Inexpensive Semiautomatic Pressurized Microfiltration DeviceE. Rodríguez-Fernandez, M. A. Vicente, J. J. Criado, and J. L. ManzanoUsing the device shown, the filtration of small volumes (= 10 mL) of liquid can be facilitated by replacing the vacuum or manual pressure on the piston with pressure exerted by a rubber band on the piston. The filtration is thus conducted in a semiautomatic way.Rodríguez-Fernandez, E.; Vicente, M. A.; Criado, J. J.; Manzano, J. L. J. Chem. Educ.2008, 85, 1051.

Laboratory Equipment / Apparatus |

Liquids |

Microscale Lab

Modification to Synthesis of Methyl DiantilisWilliam H. MilesAfter we published the Synthesis of Methyl Diantilis, a Commercially Important Fragrance,we encountered a problem with the catalyst, Amberlyst-15, used in the second step. A revised laboratory procedure has replaced the original supplement available at JCE Online.Miles, William H. J. Chem. Educ.2008, 85, 917.

Variable Temperature Equipment for a Commercial Magnetic Susceptibility BalanceAlbert LötzVariable temperature equipment for the magnetic susceptibility balance MSB-MK1 of Sherwood Scientific, Ltd., is described. Whereas the balance as sold commercially can be used only for room temperature measurements, the setup presented here extends the temperature range from 20C to 80C without a loss in performance.Lötz, Albert. J. Chem. Educ.2008, 85, 107.

Introducing Students to the Scientific LiteratureLee RoeckerDescribes an exercise in a quantitative analysis course that uses the primary literature to provide students with practice in the interpretation of statistical data, the use of spreadsheets, critical evaluation of scientific evidence, and insight into the work of analytical chemists.Roecker, Lee. J. Chem. Educ.2007, 84, 1380.

Enthalpy of Vaporization and Vapor Pressures: An Inexpensive ApparatusRubin Battino, David A. Dolson, Michael R. Hall, and Trevor M. LetcherDescribes an inexpensive apparatus for the determination of the vapor pressure of a liquid as a function of temperature for the purpose of calculating enthalpy changes of vaporization. Also described are a simple air thermostat and an inexpensive temperature controller based on an integrated temperature sensor.Battino, Rubin; Dolson, David A.; Hall, Michael R.; Letcher, Trevor M. J. Chem. Educ.2007, 84, 822.

Gases |

Laboratory Equipment / Apparatus |

Lipids |

Phenols |

Physical Properties |

Thermodynamics |

Liquids |

Phases / Phase Transitions / Diagrams

Hurricanes as Heat Engines: Two Undergraduate ProblemsPekka PyykköHurricanes can be regarded as Carnot heat engines in which evaporation of water vapor from the ocean and its subsequent condensation is the main heat transfer mechanism. The arguments presented here are simple enough to use as an illustration in a second-year chemical thermodynamics course.Pyykkö, Pekka. J. Chem. Educ.2007, 84, 447.

Thermodynamics |

Phases / Phase Transitions / Diagrams

Mercury-Free Analysis of Lead in Drinking Water by Anodic Stripping Square Wave VoltammetryJeremy P. Wilburn, Kyle L. Brown, and David E. CliffelThe analysis of drinking water for lead, which has well-known adverse health effects, provides an instructive example of the use of analytical chemistry to monitor a common hazard of everyday life. This article offers a mercury-free analytical method for the analysis of lead in drinking water using square wave anodic stripping voltammetry.Wilburn, Jeremy P.; Brown, Kyle L.; Cliffel, David E. J. Chem. Educ.2007, 84, 312.

Analysis of Phosphoric Acid Content in Popular Carbonated DrinksJessie Rodgers and Marina KoetherBy studying a number of soft drinks with color but with or without phosphoric acid, the authors have determined that the required 20-fold dilution required in the Determination of Phosphorus in Cola Drinks is not to dilute the color but merely to place the sample within the calibration range of the analysis.Rodgers, Jessie; Koether, Marina. J. Chem. Educ.2005, 82, 1471.

UV-Vis Spectroscopy |

Instrumental Methods

A Simple Low-Cost Lock-In Amplifier for the LaboratorySandip K. Sengupta, Jessica M. Farnham, and James E. WhittenThe construction of a simple, low-cost, stand-alone lock-in amplifier suitable for physical and analytical chemistry instructional laboratories is described. The instrument is useful for detecting and amplifying signals that are in-phase with a reference signal and is particularly important for optical experiments that employ a pulsed light source. Sengupta, Sandip K.; Farnham, Jessica M.; Whitten, James E. J. Chem. Educ.2005, 82, 1399.

Instrumental Methods |

Laboratory Equipment / Apparatus

NMR Analysis of Unknowns: An Introduction to 2D NMR SpectroscopyDavid E. Alonso and Steven E. WarrenSecond-year organic chemistry students analyze and compare the spectral data of three unknown ketones (2-heptanone, 3-heptanone, and 4-heptanone). Students acquire one-dimensional proton and carbon NMR data for each unknown and make signal assignments based on chemical shifts, integration values, and splitting patterns of signals. Difficulties are encountered during interpretation of NMR data for 2- and 3-heptanone. Acquiring and analyzing the two-dimensional NMR spectra of the heptanones resolve these problems. Alonso, David E.; Warren, Steven E. J. Chem. Educ.2005, 82, 1385.

Instrumental Methods |

NMR Spectroscopy |

Qualitative Analysis

Rotational Mobility in a Crystal Studied by Dielectric Relaxation Spectroscopy. An Experiment for the Physical Chemistry LaboratoryMadalena S. C. Dionísio, Hermínio P. Diogo, J. P. S. Farinha, and Joaquim J. Moura-RamosIn this article we present a laboratory experiment for an undergraduate physical chemistry course. The purpose of this experiment is the study of molecular mobility in a crystal using the technique of dielectric relaxation spectroscopy. The experiment illustrates important physical chemistry concepts. The background of the experimental technique deals with the concepts of orientational and induced polarization and frequency-dependent relative permittivity (or dielectric constant). The kinetic concepts of temperature-dependent relaxation time, activation energy, and activation entropy are involved in the concept of molecular mobility. Dionísio, Madalena S. C.; Diogo, Hermínio P.; Farinha, J. P. S.; Moura-Ramos, Joaquim J. J. Chem. Educ.2005, 82, 1355.

Kinetics |

Phases / Phase Transitions / Diagrams |

Solids |

Crystals / Crystallography

A Networked NMR Spectrometer: Configuring a Shared InstrumentDavid Alonso, G. William Mutch, Peter Wong, Steven Warren, Bal Barot, Jan Kosinski, and Mark SintonAndrews University, Lake Michigan College, and Southwestern Michigan College established an educational consortium in southwest lower Michigan. An FT-NMR spectrometer was installed at AU and networked with the community colleges. Students and faculty from LMC and SMC visit Andrews on a regular basis to receive training and operate the NMR. The instrument is accessible via the Internet for data acquisition, processing, and transfer. The spectrometer has helped the consortium schools improve the quality of chemistry education, exposed students in chemistry courses to the concepts and techniques of modern NMR spectroscopy, and strengthened the collaboration between the chemistry faculty of the three schools. This article describes the NMR network configuration and the methodology for NMR data acquisition and distribution. Alonso, David; Mutch, G. William; Wong, Peter; Warren, Steven; Barot, Bal; Kosinski, Jan; Sinton, Mark. J. Chem. Educ.2005, 82, 1342.

Instrumental Methods |

NMR Spectroscopy

An Improved Preparation of 2,4-Dinitrophenylhydrazine ReagentBen Ruekberg and Eric RossoniIn the analysis of aldehydes and ketones (both for characterizing the functional group and identifying such compounds by the melting points of their derivatives), 2,4-dinitrophenylhydrazine reagent is often used. Of the several formulations of this reagent, the most popular uses sulfuric acid. The method involves making a paste of 2,4-dinitro-phenylhydrazine in concentrated sulfuric acid, dispersion of the paste in ethanol, addition of water, and the filtration of the reagent. This improvement uses milder conditions, which may obviate the need for the final filtration. Those responsible for preparation of stock reagent solutions for classes should note that this method facilitates scaling up the preparation.Ruekberg, Ben; Rossoni, Eric. J. Chem. Educ.2005, 82, 1310.

Aldehydes / Ketones |

Laboratory Equipment / Apparatus |

Laboratory Management

Capillary Electrophoresis Analysis of Substituted Benzoic Acids. An Experiment for the Organic Synthesis LaboratoryNancy S. Mills, John D. Spence, and Michelle M. BusheyWe have introduced an experiment into the organic chemistry sequence, in the synthesis laboratory, that utilizes capillary electrophoresis to evaluate the pKa shift on a series of student-prepared substituted benzoic acids. The pKa shift is examined in reference to the electrophoretic-migration behavior of benzoic acid and is a result of the electron-withdrawing or electron-donating characteristics of the substituent. This strategy allows us to increase the exposure of students to modern methods of separation. We are using repeated exposure to increase students' knowledge of separation strategies and techniques. Mills, Nancy S.; Spence, John D.; Bushey, Michelle M. J. Chem. Educ.2005, 82, 1226.

Synthesis |

Electrophoresis |

Grignard Reagents |

Instrumental Methods |

Separation Science

Simplex Optimization of Headspace-Enrichment Conditions of Residual Petroleum Distillates Used by ArsonistsMolly M. Warnke, Angela E. Erickson, and Eugene T. SmithA forensic project is described that is suitable for an undergraduate instrumental methods lab. Accelerants commonly used by arsonists are analyzed by static headspace enrichment followed by gas chromatography. The conditions used for headspace enrichment (e.g., time and temperature) are known to influence the distribution of hydrocarbons extracted from an arson sample. To minimize artifacts associated with headspace enrichment, simplex optimization was used to determine the optimal time and temperature for the various classes of common hydrocarbon accelerants.Warnke, Molly M.; Erickson, Angela E.; Smith, Eugene T. J. Chem. Educ.2005, 82, 1082.

Chromatography |

Instrumental Methods |

Forensic Chemistry

Circular Dichroism Investigation of Dess–Martin Periodinane Oxidation in the Organic Chemistry LaboratoryNicole A. Reed, Robert D. Rapp, Christian S. Hamann, and Pamela G. ArtzUsing circular dichroism, organic laboratory students investigated the change in absolute stereochemistry upon oxidation of menthol to menthone. In the first laboratory period, the oxidation was performed with DessMartin periodinane, which is a facile and less toxic oxidizing agent. Half the laboratory group performed the oxidation with ()-menthol and the other half used (+)-menthol to produce ()-menthone and (+)-menthone, respectively. The products were analyzed in the second laboratory period using infrared spectroscopy and gas chromatography/mass spectrometry to determine the fraction of starting alcohol converted to ketone. Comparison was made between CD spectra both for the menthol reactant and menthone product and for the (+)- and ()-menthone enantiomers.Reed, Nicole A.; Rapp, Robert D.; Hamann, Christian S.; Artz, Pamela G. J. Chem. Educ.2005, 82, 1053.

Teaching pH Measurements with a Student-Assembled Combination Quinhydrone ElectrodeFritz Scholz, Tim Steinhardt, Heike Kahlert, Jens R. Pörksen, and Jürgen BehnertA combination pH electrode that can be assembled by the student is described. It consists of a glass holder and two sensors in the form of rubber stoppers that contain quinhydrone and graphite. The combination electrode is suitable to teach potentiometric measurements, pH measurements, and the interplay of acidbase and redox equilibria. The electrode meets highest safety standards and overcomes the troubles associated with the use of the conventional quinhydrone electrode.Scholz, Fritz; Steinhardt, Tim; Kahlert, Heike; Pörksen, Jens R.; Behnert, Jürgen. J. Chem. Educ.2005, 82, 782.

Acids / Bases |

pH |

Laboratory Equipment / Apparatus |

Electrochemistry

Understanding Mass Spectra, A Basic Approach, Second Edition (R. Martin Smith)Bill BoggessThe interpretation of mass spectra represents arguably the most significant challenge to both newcomers and practitioners in the field of mass spectrometry (MS). For those of us who have ever struggled to use a mass spectrum to solve the structure of an organic compound, R. Martin Smith offers the second edition of Understanding Mass Spectra, A Basic Approach. Fortunately, the author manages to go well beyond the obvious and expected explanations of the common modes of fragmentation for ions generated during electron ionization (EI) by offering a rational approach to mass spectral problem solving. This ten-step approach, which represents the most important contribution of this text, appears in chapter 5 and is condensed into table 5.1. Boggess, Bill. J. Chem. Educ.2005, 82, 687.

Mass Spectrometry |

Instrumental Methods

Automatic Low-Cost Data Acquisition from Old Polarimetric InstrumentsGiuseppe Alibrandi, Santi D'Aliberti, Salvatore Coppolino, Antonino Villari, and Norberto MicaliThis article describes the design of an apparatus that allows the digital acquisition of polarimetric data from a Lippich polarimeter. This apparatus consists of a low-cost telecamera applied to the ocular of a double-field polarimeter and connected to a PC. The camera is able to reveal with high sensibility the difference in brightness in the two fields allowing more accurate analytical data to be obtained, without need for the analyser to be rotated. This apparatus allows the execution of either single observations or kinetics, because it is able to save previously obtained analytical data. Alibrandi, Giuseppe; D'Aliberti, Santi; Coppolino, Salvatore; Villari, Antonino; Micali, Norberto. J. Chem. Educ.2005, 82, 442.

Instrumental Methods |

Kinetics |

Quantitative Analysis |

Laboratory Equipment / Apparatus

A Chemometrics Module for an Undergraduate Instrumental Analysis Chemistry CourseHuggins Z. Msimanga, Phet Elkins, Segmia K. Tata, and Dustin Ryan SmithA chemometrics module for the undergraduate instrumental analysis chemistry course was developed and implemented. The objective of this module is to provide the skills needed by students to design experiments, to learn calibration techniques for analyzing multicomponent systems, to extract chemical information from large data sets provided by modern instruments, and, overall, to provide a broader spectrum of analytical techniques especially for those students who aspire going to graduate schools or working in chemical industries.Msimanga, Huggins Z.; Elkins, Phet; Tata, Segmia K.; Smith, Dustin Ryan. J. Chem. Educ.2005, 82, 415.

Instrumental Methods |

UV-Vis Spectroscopy |

Chemometrics |

Instrumental Methods

Environmental Laboratory Exercises for Instrumental Analysis and Environmental Chemistry (Frank M. Dunnivant)Marco A. De JesúsEnvironmental Laboratory Exercises for Instrumental Analysis and Environmental Chemistry is a good reference for educators involved in the design of an introductory environmental or instrumental chemistry laboratory. The manual contains 28 laboratory exercises grouped in seven core areas encompassing fundamental laboratory techniques, analysis of air contaminants, aquatic chemistry, hazardous waste analysis, soil chemistry, natural waters analysis, and fate and transport modeling of environmental pollutants. The text comes with a CD-ROM that contains additional problems for the students and an electronic version of the supportive material. The CD also includes a series of interactive Shockwave simulations that models distribution coefficient of different acidbase systems and the fate and transport of a contaminant in a variety of environmental matrices.De Jesús, Marco A. J. Chem. Educ.2005, 82, 382.

Fractional Distillation of Air and Other Demonstrations with Condensed GasesMaria Oliver-Hoyo and William L. Switzer, IIIThis demonstration builds upon the commonly performed liquefaction of air not only to show the presence of nitrogen and oxygen, but also the presence of two other components, carbon dioxide and water. Several extensions are suggested: one to show boiling point elevation in solution and another to show the elevation of both boiling point and sublimation point with pressure. No special apparatus is required permitting presentations to audiences in a variety of settings. These demonstrations give the opportunity to discuss properties of gases, solution chemistry, and phase equilibria.Oliver-Hoyo, Maria; Switzer, William L., III. J. Chem. Educ.2005, 82, 251.

Remote Instrumentation for the Teaching LaboratoryJit Baran, Ron Currie, and Dietmar KennepohlChemistry has traditionally been one of the more difficult subjects to teach at a distance owing mostly to challenges in delivering the laboratory component. It is now possible to control analytical instruments in real time and carry out computer-interfaced instrumental chemistry experiments remotely via an Internet connection. Baran, Jit; Currie, Ron; Kennepohl, Dietmar. J. Chem. Educ.2004, 81, 1814.

Instrumental Methods

Initial Design and Development of an Integrated Laboratory Network: A New Approach for the Use of Instrumentation in the Undergraduate CurriculumDevon A. CancillaThis paper describes both the conceptual framework and initial development of Western Washington University's Integrated Laboratory Network (ILN). The ILN brings together scientific instrumentation, Internet-based classroom management systems (CMS), and other online resources to provide a new working model for the use and introduction of instrumentation within the undergraduate curriculum. Full implementation of the ILN will allow greater access to instruments and instrumental data and will provide a wide variety of novel teaching and learning opportunities. Cancilla, Devon A. J. Chem. Educ.2004, 81, 1809.

Laboratory Computing / Interfacing |

Instrumental Methods

Students' Attitudes toward and Conceptual Understanding of Chemical InstrumentationLarry S. Miller, Mary B. Nakhleh, John J. Nash, and Jeanne A. MeyerData collected from field notes, surveys, and interviews are used to evaluate (i) the attitudes students have toward using instrumentation, (ii) how students relate the underlying chemical concepts to the instrumentation, and (iii) how working in a group impacts students' attitudes toward, and their conceptual understanding of, chemical instrumentation. Miller, Larry S.; Nakhleh, Mary B.; Nash, John J.; Meyer, Jeanne A. J. Chem. Educ.2004, 81, 1801.

Gravimetric Titrations: In Support of Weight Titration TechniquesRichard W. RametteI write in support of the recommendations of Stephen Hawkes on gravimetric titrations. Weight titration techniques are, in my opinion, by far the best way to bring volumetric analysis into the 20th (let alone 21st) century. Ramette, Richard W. J. Chem. Educ.2004, 81, 1715.

Studying Current–Potential Curves Using Bipotentiometric Iodometric Back-Titration for the Determination of Ascorbic Acid in Fruits and VegetablesRoxana A. Verdini and Claudia M. LagierA method for the determination of the ascorbic acid content in fruits and vegetables was used to introduce the principles of voltammetry. The procedure combines an iodometric back-titration with voltammetric (bipotentiometric) end point detection, which minimizes the risk of ascorbic acid oxidation, allowing for a rapid and efficient quantification of vitamin C in fruits and vegetables. A better understanding of the titration curve is achieved by analyzing the schematic currentpotential curves of the anodic and cathodic half-cell reactions during the titration. Verdini, Roxana A.; Lagier, Claudia M. J. Chem. Educ.2004, 81, 1482.

Constitutional Isomers |

Electrochemistry |

Food Science |

Instrumental Methods |

Oxidation / Reduction |

Titration / Volumetric Analysis |

Vitamins |

Consumer Chemistry

Use of a Tea Infuser To Submerge Low-Density Dry IceCarl P. FictorieA tea infuser is used as a container to hold low-density dry ice. When used with the classic demonstration where dry ice is used to acidify a solution in a graduated cylinder, the dry ice is suspended in the middle of the cylinder, allowing the solution in the upper half of the cylinder to change color while the lower half remains unchanged. Phase changes, acidbase chemistry, and diffusion phenomena are all illustrated. Fictorie, Carl P. J. Chem. Educ.2004, 81, 1473.

Acids / Bases |

Aqueous Solution Chemistry |

Laboratory Equipment / Apparatus |

Phases / Phase Transitions / Diagrams

A Simple, Inexpensive Water-Jacketed Cuvette for the Spectronic 20Jonathan E. Thompson and Jason TingA simple, inexpensive, water-jacketed cuvette for the Spectronic 20 is described. The cuvette and associated flow system can easily be constructed from materials commonly found in an undergraduate chemistry laboratory. As a demonstration of the cuvette's utility, we used the cuvette for the determination of the activation energy for the reaction between crystal violet and hydroxide ion. However, the cuvette may prove useful in a variety of applications in which a sample must be thermostated within a spectrophotometer. Thompson, Jonathan E.; Ting, Jason. J. Chem. Educ.2004, 81, 1341.

Laboratory Equipment / Apparatus |

Kinetics |

Spectroscopy

The History of Ion Chromatography: The Engineering PerspectiveBarton EvansThis article traces the history of the engineering development related to the several generations of ion chromatography instruments, columns, suppressers, and software. In so doing, several representative engineering challenges and their outcomes are discussed including: early directions (traveling without a road map, or "going where the applications are"), dealing with an extremely corrosive mobile phase (aka: the "eluent"), resolving the inherent incompatibilities of nonmetallic flow paths with the benefits of high-pressure, elevated temperature operation, managing the ever-evolving nature of the suppressor, coping with requirements for ultra high-end online systems, and providing extremely simple-to-use dedicated analyzer systems. Evans, Barton. J. Chem. Educ.2004, 81, 1285.

Chromatography |

Industrial Chemistry |

Instrumental Methods |

Ion Exchange |

Laboratory Equipment / Apparatus |

Separation Science |

Water / Water Chemistry

Ion Chromatography: An Account of Its Conception and Early DevelopmentHamish SmallIn the late 1950s, a small group of chemists at the Dow Chemical Company envisioned replacing these classical methods of inorganic analysis with but a single, universal chromatographic technique. They called their project "Inorganic Chromatography". This article describes how they developed this concept into a new technique, ready for commercial development into what we know today as "Ion Chromatography". In particular, the account will describe: how the Dow scientists adapted electrical conductance monitoring to chromatography, the introduction of the suppressor to chromatography, the invention of special stationary phases, and the evolution of strategies and principles that would shape and guide the practice of ion chromatography for many years to come. Small, Hamish. J. Chem. Educ.2004, 81, 1277.

Chromatography |

Industrial Chemistry |

Instrumental Methods |

Ion Exchange |

Laboratory Equipment / Apparatus |

Separation Science |

Water / Water Chemistry

The 12th Annual James L. Waters Symposium at Pittcon: Ion ChromatographyAdrian C. MichaelThe objectives of the annual James L. Waters Symposium at Pittcon are to explore the origins, development, and commercialization of scientific instrumentation of established and major significance. The topic of the twelfth Waters Symposium was ion chromatography; three of those papers are featured in this issue of the Journal.Michael, Adrian C. J. Chem. Educ.2004, 81, 1277.

Chromatography |

Conferences |

Instrumental Methods

The Purification of Water by Zone Melting: A Phase Diagram InterpretationMohamed JemalOughton, Xu, and Battino published a paper in this Journal on the application of zone melting to the purification of water from NaCl aqueous solutions. I would like to comment on this interesting paper by giving an interpretation of some of their results taking into account the binary phase diagram.Jemal, Mohamed. J. Chem. Educ.2004, 81, 952.

Chem 111: A General Education Course in Organic Structure DeterminationStuart C. Clough, René P. F. Kanters, and Emma W. GoldmanA course in organic structure determination has proven to be effective in addressing the general education science requirement for liberal arts and business majors who have only a basic high school chemistry background.Clough, Stuart C.; Kanters, René P. F.; Goldman, Emma W. J. Chem. Educ.2004, 81, 834.

Nonmajor Courses |

Instrumental Methods

Boiling Point versus MassMichael LaingI am very pleased that Ronald Rich has written making these comments, because he is pre-eminent in this field, beginning with his early book, Periodic Correlations.Laing, Michael. J. Chem. Educ.2004, 81, 642.

Atomic Properties / Structure |

Molecular Properties / Structure |

Noncovalent Interactions |

Liquids |

Phases / Phase Transitions / Diagrams

Boiling Point versus Mass Ronald L. RichLaing gave a useful examination of the boiling points of small molecules versus molecular mass. However, a molecule escaping from a liquid is not closely analogous to a satellite breaking free from the earths gravitational field with the requirement of a minimum escape velocity, such that the required kinetic energy is proportional to the mass of the satellite at that escape velocity.Rich, Ronald L. J. Chem. Educ.2004, 81, 642.

Questioning an Ultrasonic Lab SetupFrancisco J. ArnáizThe intermediate referred to as an oxyallyl cation is not a cation but a zwitterion, and the mentioned by-product, CuI2 (crucial to explain the need of excess copper referred to in the text, since in fact CuI is formed) is nonexistent.Arnáiz, Francisco J. J. Chem. Educ.2004, 81, 193.

Laboratory Equipment / Apparatus |

Metals |

Microscale Lab

Questioning an Ultrasonic Lab SetupFrancisco J. ArnáizThe intermediate referred to as an oxyallyl cation is not a cation but a zwitterion, and the mentioned by-product, CuI2 (crucial to explain the need of excess copper referred to in the text, since in fact CuI is formed) is nonexistent.Arnáiz, Francisco J. J. Chem. Educ.2004, 81, 193.

Build a Simple PolarimeterFrank E. Stary and Norman WoldowDetails of the construction of a durable, inexpensive portable polarimeter with a self-contained 585-nm light source are given, combining the best features of several polarimeters; may easily be scaled up in size for increased sensitivity. Stary, Frank E.; Woldow, Norman. J. Chem. Educ.2001, 78, 644.

Instrumental Methods |

Kinetics |

Laboratory Equipment / Apparatus |

Stereochemistry

Are Fizzing Drinks Boiling? A Chemical Insight from Chemical Education ResearchAlan GoodwinThe suggestion that fizzing drinks are examples of liquids boiling at room temperature has proved to be controversial among both chemists and chemical educators. This paper presents a case for believing this everyday system to be a good example of a boiling solution and the consequent separation of carbon dioxide from the solution to exemplify fractional distillation. Goodwin, Alan. J. Chem. Educ.2001, 78, 385.

Aqueous Solution Chemistry |

Kinetic-Molecular Theory |

Equilibrium |

Gases |

Solutions / Solvents |

Phases / Phase Transitions / Diagrams

Safe and Efficient Flash Chromatography Equipment for the Research/Teaching LabFritiof Pontén and Ulf EllervikA new method for performing flash chromatography is presented in which the solvent reservoir is at the side of the column, in a separate bottle, connected with a Teflon tube to an adapter for standard flash chromatography columns. Pontén, Fritiof; Ellervik, Ulf. J. Chem. Educ.2001, 78, 363.

Chromatography |

Laboratory Equipment / Apparatus |

Separation Science

Using a Diode Laser Pointer to Count Drops and Automate Titration SystemsPaul Ogren, Steve Nelson, and Ian HenryA diode laser pointer is used to construct a simple system for recording drops falling from a buret. The drop signal is recorded together with one or more measurement signals by a LabVIEW-based programmable interfacing system. A standard buret is converted to a Mariotte buret to provide a constant drop-addition rate.Ogren, Paul; Nelson, Steve; Henry, Ian. J. Chem. Educ.2001, 78, 353.

Laboratory Computing / Interfacing |

Quantitative Analysis |

Instrumental Methods

Surface Tension Determination through Capillary Rise and Laser Diffraction PatternsTeresita Munguia and Charles A. SmithIn this physical chemistry experiment the surface tension of several solvents is determined by measuring the height of the capillary rise in a capillary tube; the radius of the tubing is calculated through measurements taken from the diffraction pattern produced when a laser of known wavelength is passed through a short piece of the capillary tubing.Munguia, Teresita; Smith, Charles A. J. Chem. Educ.2001, 78, 343.

A Short History of the Chemical ShiftSamuel G. LevineThe term chemical shift is shown to have originated in the mistaken assumption that nuclei of a given element will all undergo resonance at the same frequency regardless of their environment. Levine, Samuel G. J. Chem. Educ.2001, 78, 133.

Infrared Spectroscopy in the General Chemistry LabMargaret A. HillThree laboratory exercises in which students learn to interpret infrared spectra for simple structural identification. A polymer identification lab uses familiar household polymer samples and teaches students how to use infrared spectral data to determine what bond types are present in the polymers. In a second lab, students learn to prepare potassium bromide pellets of fluorene derivatives and identify them by their functional group differences. The final exercise combines IR with several other lab techniques to identify an organic acid from a field of fourteen possibilities.Hill, Margaret A. J. Chem. Educ.2001, 78, 26.

Evaporation Kinetics in Short-Chain Alcohols by Optical InterferenceIan M. Rosbrugh, S. Y. Nishimura, and A. M. NishimuraThe evaporation rates of volatile organic liquids may be determined through the observation of optical interference of spatially coincident light that is reflected from the top (air-liquid) and bottom (liquid-surface) of a liquid drop on a glass surface. As an example of what is possible with this technique, the evaporation for a series of short-chain alcohols and acetone is investigated.Rosbrugh, Ian M.; Nishimura, S. Y.; Nishimura, Allan M. J. Chem. Educ.2000, 77, 1047.

Kinetics |

Laboratory Equipment / Apparatus |

Liquids

An Inexpensive Gradient Maker for the Biochemistry LaboratoryWilliam H. FlurkeyA gradient maker for use in the biochemistry laboratory was constructed out of plastic graduated cylinders or other easily obtained plastic items. Assembly of the gradient makers requires little time or expense. Details on construction and operation are given.Flurkey, Bill. J. Chem. Educ.2000, 77, 1041.

Glass Doesn't Flow and Doesn't Crystallize and It Isn't a LiquidStephen J. HawkesIt is widely believed that glass flows in historic time and it is often asserted that glass is a liquid. The evidence of archeology, geology, and viscosity and of research on glass structure and on conservation of antique glass is examined and the conclusion in the title is reached. These fallacies should not be taught. Hawkes, Stephen J. J. Chem. Educ.2000, 77, 846.

Geochemistry |

Phases / Phase Transitions / Diagrams |

Solid State Chemistry

Melting Point and Molecular SymmetryR. J. C. Brown and R. F. C. BrownIn 1882 Thomas Carnelley observed that high molecular symmetry is associated with high melting point. The application of the rule to a number of different molecular crystals is discussed. The rule applies to different categories of crystal for different reasons, which can be explained by thermodynamic analysis.Brown, R. J. C.; Brown, R. F. C. J. Chem. Educ.2000, 77, 724.

Liquids |

Molecular Properties / Structure |

Phases / Phase Transitions / Diagrams |

Solids |

Thermodynamics |

Physical Properties |

Aromatic Compounds |

Crystals / Crystallography

A Closer Look at Phase Diagrams for the General Chemistry CourseStephen A. GramschThe information provided by the high-pressure phase diagrams of some simple systems (carbon dioxide, water, hydrogen, and iron) can provide a useful extension to the traditional discussion of phase diagrams in the general chemistry course. At the same time, it can prepare students for a more illuminating presentation of the concept of equilibrium than is possible through the discussion of gas phase, acid-base, and solubility product equilibria alone. Gramsch, Stephen A. J. Chem. Educ.2000, 77, 718.

Equilibrium |

Phases / Phase Transitions / Diagrams |

Thermodynamics |

Geochemistry

Instrumental Analysis Lecture and Laboratory: A SurveyJames E. Girard and Constance T. DiamantWhich topics should be covered in instrumental analysis lecture and which instrumental techniques should be used in the instrumental laboratory? We surveyed a randomly chosen group of analytical chemistry faculty. It appears that there is a consensus about which experimental techniques the instrumental course should offer to undergraduates. Girard, James E.; Diamant, Constance T. J. Chem. Educ.2000, 77, 646.

Instrumental Methods

Dry-Ice Bath Based on Ethylene Glycol MixturesDo W. Lee and Craig M. JensenBath mixtures of ethanol and ethylene glycol in dry ice produce sustainable constant temperatures over the range from -12 to -78 C, is less toxic than previously reported mixtures of ortho- and meta-xylene, does not intractably solidify as will dry ice slurries of xylenes, and is less costly than xylene mixtures. Lee, Do W.; Jensen, Craig M. J. Chem. Educ.2000, 77, 629.

A Simple Laboratory-Constructed Automatic TitratorKurt L. Headrick, Terry K. Davies, and Aaron N. HaegeleThe construction of a simple automatic titrator is described. The buret is replaced with a metering pump to provide a constant flow of titrant. The output from the pH meter is sent to a recorder via a laboratory- constructed differentiator, allowing the results to be plotted as potential versus time, first or second derivativeHeadrick, Kurt L.; Davies, Terry K.; Haegele, Aaron N. J. Chem. Educ.2000, 77, 389.

Instrumental Methods |

Acids / Bases |

Laboratory Equipment / Apparatus |

Quantitative Analysis |

Titration / Volumetric Analysis

Rapid, Simple Quantitation in Thin-Layer Chromatography Using a Flatbed ScannerMitchell E. JohnsonSimply scanning a visibly stained TLC plate into a computer substitutes for much more expensive plate readers. With common image analysis software, "elution" profiles can be obtained. The resulting "chromatograms" can be analyzed in the same manner as other chromatograms. Johnson, Mitchell E. J. Chem. Educ.2000, 77, 368.

Chromatography |

Instrumental Methods |

Laboratory Equipment / Apparatus |

Quantitative Analysis |

Thin Layer Chromatography

Determination of the Scoville Heat Value for Hot Sauces and Chilies: An HPLC ExperimentJames D. Batchelor and Bradley T. JonesThe student will isolate the capsainoids from commercial food products (chilies and sauces) using a simple extraction technique. The identity and concentration of the capsainoids are determined by high-performance liquid chromatography (HPLC). The concentrations are then used to determine the pungency (Scoville heat value) of the foods. Batchelor, James D.; Jones, Bradley T. J. Chem. Educ.2000, 77, 266.

Instrumental Methods |

Chromatography |

Food Science |

Applications of Chemistry

An Inexpensive Commercially Available Analog-to-Digital ConverterGary W. BretonThe use of an inexpensive analog-to-digital converter for interfacing gas chromatographs to computers in a teaching laboratory environment is described. Raw data may be read, processed, and printed from software supplied with the converter to afford chromatograms of acceptable quality. Breton, Gary W. J. Chem. Educ.2000, 77, 262.

Instrumental Methods |

Laboratory Computing / Interfacing |

Laboratory Equipment / Apparatus |

Chromatography

A Low-Cost Device for Automatic Photometric TitrationsFábio R. P. Rocha and Boaventura F. ReisConstruction of a simple, low-cost (about $150 U.S.) automatic photometric titrator employing a light-emitting diode (LED) and a phototransistor. The electronic circuit can be assembled by the students themselves. The device was employed to implement a common procedure in chemical labs, making feasible the introduction of concepts related to electronics in undergraduate chemistry courses.Rocha, Fbio R. P.; Reis, Boaventura F. J. Chem. Educ.2000, 77, 258.

Instrumental Methods |

Quantitative Analysis |

Titration / Volumetric Analysis |

Laboratory Equipment / Apparatus

Calculator-Based Instrumentation: The Design of a Digital Interface Based on I2C TechnologyA. B. Hickman, W. G. Delinger, and Robin S. HelburnIn this work, we describe the interfacing of a digital temperature sensor to a Texas Instruments TI-85 calculator to make a portable instrument. The design of the interface is based on an integrated circuit that uses the inter-integrated circuit (I2C) protocol. Hickman, A. B.; Delinger, W. G.; Helburn, Robin S. J. Chem. Educ.2000, 77, 255.

Instrumental Methods |

Laboratory Computing / Interfacing |

Laboratory Equipment / Apparatus

Reply to Inflection at the Triple PointMyers, R. ThomasResponse to challenges in graphing the triple point of water and correction to original article.Myers, R. Thomas J. Chem. Educ.2000, 77, 160.

LettersChallenges in graphing the triple point of water.J. Chem. Educ.2000, 77, 160.

Phases / Phase Transitions / Diagrams |

Physical Properties |

Water / Water Chemistry

The Development of Innovative Laboratory Experiments with UV-Visible SpectrophotometerPeter Abeta IyereA brief description of the instrument acquired with National Science Foundation funds (Cary 300 BIO UV-Vis Spectrophotometer, model EL98013047 equipped with diffuse reflectance and temperature control accessories) precedes highlights of some of the experiments being developed at Tennessee State University.Iyere, Peter Abeta. J. Chem. Educ.2000, 77, 153.

UV-Vis Spectroscopy |

Instrumental Methods |

Laboratory Equipment / Apparatus

Understanding NMR Multiplet Structure with WinDNMRN. Bampos and A. Vidal-FerranEmploying interactive, user-friendly software packages (such as WinDNMR) on a conventional personal computer to investigate the effect of changing the constituent coupling constants on the appearance of a multiplet. As an example, a multiplet representing a proton coupled to three neighboring environments (four-spin system) is treated in detail. Bampos, N.; Vidal-Ferran, A. J. Chem. Educ.2000, 77, 130.

NMR Spectroscopy |

Instrumental Methods

A Simple Hanging Mercury Drop ElectrodeFlorinel Gabriel BanicaA device producing reproducible hanging mercury drops at the end of a glass capillary is described. Mercury flow through the capillary is controlled by means of a closing needle actuated by an electromagnetic relay. The timing circuit is very simple and consists only of resistors and capacitors.Banica, Florinel Gabriel. J. Chem. Educ.2000, 77, 98.

Instrumental Methods |

Electrochemistry |

Laboratory Equipment / Apparatus

Easy-to-Make Ag/AgCl Reference ElectrodeGaston A. East and M. A. del ValleIn this contribution we describe the construction of a silver-silver chloride reference electrode that can be readily assembled in any teaching laboratory and that fulfills most of the requirements expected for a device of this kind. East, Gaston A.; del Valle, M. A. J. Chem. Educ.2000, 77, 97.

Analysis of Semivolatile Organic Compounds in Fuels Using Gas Chromatography-Mass SpectrometryTal M. NahirThe analysis of diesel fuel using gas chromatography-mass spectrometry is described. The experiment is especially appropriate for courses in instrumental analysis and environmental chemistry. Results from the injections of small amounts of liquid samples include total-ion- and single-ion-mode chromatograms as well as mass spectra of polycyclic aromatic hydrocarbon derivatives. Nahir, Tal M. J. Chem. Educ.1999, 76, 1695.

Chromatography |

Instrumental Methods |

Mass Spectrometry

Constructing Environmental Impact Statements. An Organizational Focus for Teaching Analytical Environmental ChemistrySusan M. LibesPreparation of an environmental impact statement (EIS) is the organizational focus for an undergraduate lab course in environmental chemistry. Students work collaboratively through the semester to prepare an EIS following National Environmental Policy Act (NEPA) guidelines. This involves several stages of activity including a scoping process, field sampling, and laboratory analyses, modeling of the results to predict impacts, and report writing. Libes, Susan. J. Chem. Educ.1999, 76, 1649.

Environmental Chemical Analysis (by B. B. Kebbekus and S. Mitra)reviewed by Nathan W. BowerThis text helps to fill a void in the market, as there are relatively few undergraduate instrumental analysis texts designed specifically for the expanding population of environmental science students.Bower, Nathan W. J. Chem. Educ.1999, 76, 1489.

Instrumental Methods

A Simple Supplementary Offset Device for Data Acquisition SystemsThomas Kappes and Peter C. HauserThe device described in this article offers in a simple way the possibility of extending the offset range and can be combined with any data acquisition system. The signal offset is obtained by adding a manually adjustable voltage to the raw signal.Kappes, Thomas; Hauser, Peter C. J. Chem. Educ.1999, 76, 1429.

Instrumental Methods |

Laboratory Equipment / Apparatus

Entropy, Disorder, and FreezingBrian B. LairdIt is argued that the usual view that entropy is a measure of "disorder" is problematic and that there exist systems at high density, for which packing considerations dominate, where a spatially ordered state has a higher entropy than a disordered one. Laird, Brian B. J. Chem. Educ.1999, 76, 1388.

An Apparatus for Temperature DisplaysGeorge Papageorgiou and John XenosIn this article, a new simple and low-cost apparatus is introduced that provides the possibility to display temperature measurements in any lecture hall. The apparatus provides analog displays. Its construction requires only simple and inexpensive materials.Papageorgiou, George; Xenos, John. J. Chem. Educ.1999, 76, 1094.

A More Dramatic Container to Crush by Atmospheric PressureRobert D. Meyers and Gordon T. YeeThe familiar demonstration of collapsing a can by filling it with water vapor and then sealing it and allowing it to cool is improved by performing it with a 20-L steel solvent drum instead. Meyers, Robert D.; Yee, Gordon T. J. Chem. Educ.1999, 76, 933.

Correction to The Bobbing BirdGesser, Hyman D.Problem with demonstration if humidity is high and correction for this.Gesser, Hyman D. J. Chem. Educ.1999, 76, 757.

Phases / Phase Transitions / Diagrams

Introducing a Practice-Oriented Approach in the Physical Chemistry Instructional LaboratoryDavid E. Budil, Lutfur R. Khundkar, Ihsan A. Shehadi, and Mary Jo OndrechenThere remains a tendency to follow the traditional philosophy that physical principles are to be illustrated experimentally rather than applied in problem solving, often with complex apparatus that distracts students from the point of the experiment. Budil, David E.; Khundkar, Lutfur R.; Shehadi, Ihsan A.; Ondrechen, Mary Jo. J. Chem. Educ.1999, 76, 601.

Instrumental Methods

A GC Instrument SimulatorD. Bruce ArmitageThis simulator was developed to help students beginning the study of gas chromatographic instruments to understand their operation. It is not meant to teach chromatographic theory. Armitage, D. Bruce. J. Chem. Educ.1999, 76, 287.

Chromatography |

Instrumental Methods |

Gas Chromatography

Pungency Quantitation of Hot Pepper Sauces Using HPLCThomas A. BettsThe format of the laboratory described here allows students to collectively develop an HPLC method for the quantitation of the two predominant capsaicinoids (capsaicin and dihydrocapsaicin) in hot-pepper products. Each small group of students investigated one of the following aspects of the method: detector wavelength, mobile-phase composition, extraction of capsaicinoids, calibration, and quantitation. The format of the lab forced students to communicate and cooperate to develop this method. Betts, Thomas A. J. Chem. Educ.1999, 76, 240.

Incorporation of GC-MS into an Environmental Science CurriculumAudrey E. McGowin and George G. HessIncorporating modern analytical instrumentation such as GC-MS into an interdisciplinary environmental science program presents many challenges. The most daunting challenge is the variety of disciplines from which students come and their limited understanding of chemistry and chemical analysis.McGowin, Audrey E.; Hess, George G. J. Chem. Educ.1999, 76, 23.

A Simple Electrochemical Approach to Heterogeneous Reaction KineticsK. J. Drok, I. M. Ritchie, and G. P. PowerThe system studied is the dissolution of a known amount of copper in a solution of iron(III). The reaction time is determined by measuring the potential of the copper, which has been electrodeposited on an inert electrode, as a function of timeDrok, K. J.; Ritchie, Ian M.; Power, G. P. J. Chem. Educ.1998, 75, 1145.

Instrumental Methods |

Electrochemistry |

Kinetics

A Solid-State Water Flow Fault Safety Switch for the Chemical LaboratoryJonas Gruber, Rosamaria Wu Chia Li, and Isaac GruberA low cost solid-state water flow fault switch with a thermal sensing device is described that cuts the electric power of the heating element, normally employed in distillation and reflux devices, whenever their cooling water streams are impaired. This to prevent any possible escape of distillate vapours which may be toxic or flammable.Gruber, Jonas; Li, Rosamaria Wu Chia; Gruber, Isaac. J. Chem. Educ.1998, 75, 1132.

Instrumental Methods |

Laboratory Equipment / Apparatus |

Laboratory Management

An Inexpensive Detector for Gas ChromatographyAllan L. Smith, Edward J. Thorne, and Wolfgang NadlerWe have developed a low-cost (parts cost approximately $70) detector that can be used in a freshman level class to demonstrate the fundamental principles of gas chromatography (GC). The detector box can be used in a modification of experiments available in the literature which do not enable a quantitative method of analysis. We have used it with success in a freshman class of approximately 450 students in an experiment to separate chlorinated hydrocarbons via GC. Smith, Allan L.; Thorne, Edward J.; Nadler, Wolfgang. J. Chem. Educ.1998, 75, 1129.

Capillary Electrophoresis in the Analytical and Physical Chemistry LaboratoriesKathryn R. WilliamsAvailability of capillary electrophoresis (CE) instrumentation allows students to have hands-on experience with this modern separation tool. They gain more than operational knowledge, however. Inherent in the instructional process is an emphasis on the relation of the chemistry of the sample to the fundamental mechanism of electrophoresis and the demonstration of how CE complements other methods for similar measurements. Williams, Kathryn R. J. Chem. Educ.1998, 75, 1079.

Separation Science |

Laboratory Equipment / Apparatus

Design and Operation of a Portable Quadrupole Mass Spectrometer for the Undergraduate CurriculumMichael Henchman and Colin SteelWe describe the design and construction of a teaching mass spectrometer from components that are available commercially. The instrument is transportable, robust, and inexpensive. It yields a mass spectrum 3 minutes after being switched on and is designed to be used by undergraduates and maintained by faculty without special instrumental skills.Henchman, Michael; Steel, Colin. J. Chem. Educ.1998, 75, 1042.

Instrumental Methods |

Laboratory Equipment / Apparatus |

Mass Spectrometry |

Computational Chemistry

Laboratory Made Electrochemical Sensors for Adsorptive Stripping VoltammetryTeresa GoscinskaA novel method of adsorptive stripping voltammetry with a medium exchange preconcentration for the analytical detection of ferrocene in a small sample is presented. A laboratory prepared carbon paste electrode or a clay modified carbon paste electrode (referred to as a sensor) is used as a working electrode.Goscinska, Teresa. J. Chem. Educ.1998, 75, 1038.

Electrochemistry |

Laboratory Equipment / Apparatus |

Microscale Lab

An Experiment in the Sampling of Solids for Chemical AnalysisRobert D. Guy, Louis Ramaley, and Peter D. WentzellAn experiment is described that is suitable for demonstrating the principles of sampling uncertainty in the chemical analysis of particulate materials. Although uncertainty due to the sampling of heterogeneous materials is a pervasive problem in the analysis of "real world" samples, there are very few experiments designed to introduce this topic into the undergraduate laboratory. Guy, Robert D.; Ramaley, Louis; Wentzell, Peter D. J. Chem. Educ.1998, 75, 1028.

Laboratory Equipment / Apparatus |

Solids

The Thermometer as a Simple InstrumentGeorge F. AtkinsonThe liquid-in-glass thermometer is used as a simple example of designing a measurement instrument which requires no previous knowledge of topics like electricity or optics. Atkinson, George F. J. Chem. Educ.1998, 75, 849.

Laboratory Equipment / Apparatus |

Instrumental Methods

A Standardized Approach to Collecting and Calculating Noise Amplitude SpectraNorman N. Sesi, Mathew W. Borer, Timothy K. Starn, and Gary M. HieftjeA standardized approach to acquire, calculate, and display noise spectra is proposed. The method is based on normalizing the noise amplitude spectrum to the average dc level of the input signal. This normalization procedure should allow noise spectra, obtained in different laboratories or from different sources, to be compared both quantitatively and qualitatively. Sesi, Norman N.; Borer, Mathew W.; Starn, Timothy K.; Hieftje, Gary M. J. Chem. Educ.1998, 75, 788.

Quantitative Analysis |

Laboratory Equipment / Apparatus |

Instrumental Methods |

Spectroscopy

Teaching Computer Concepts to Undergraduate ChemistsRonald S. HainesA curriculum for introducing chemistry students to the use of computer hardware and software in chemistry is described. The aim of the curriculum is to give students confidence when dealing with computers by emphasizing underlying concepts which are common to many computer applications.Haines, Ronald S. J. Chem. Educ.1998, 75, 785.

Learning Theories |

Laboratory Equipment / Apparatus

Modified Carbon Electrodes for Microscale ElectrochemistryEnrico Mocellin and Teresa GoscinskaThis paper tries to communicate the surface chemistry nature of electrochemistry, while conveying the future possibilities and application of the subject in such a way that the students may gain some insight and venture to explore the modern methodology and its future directions. Mocellin, Enrico; Goscinska, Teresa. J. Chem. Educ.1998, 75, 771.

Laboratory Equipment / Apparatus |

Electrochemistry |

Microscale Lab |

Synthesis

Claisen's Flask and Its EvolutionBruno LunelliThe current note presents two types of semimicro distilling flask, plus a vapor condenser, all exploiting a centrifugal field, (together with an order-of-magnitude calculation of the field's strength). Lunelli, Bruno. J. Chem. Educ.1998, 75, 638.

Laboratory Equipment / Apparatus

A Low-Cost Auto-Stop Hydraulic Press for Making KBr DiscPing-Kay HonA hydraulic press fitted with an adjustable torque wrench, together with a stand made of iron bars will form an auto-stop hydraulic press for making KBr disc in IR studies. Total material cost is about $100.Hon, Ping-Kay. J. Chem. Educ.1998, 75, 629.

Determining the Authenticity of Gemstones Using Raman SpectroscopyAaron Aponick, Emedio Marchozzi, Cynthia R. Johnston, and Carl T. WigalThis paper reports the development of an experiment using Raman spectroscopy which determines the authenticity of both diamonds and pearls. The resulting spectra provide an introduction to vibrational spectroscopy and can be used in a variety of laboratory courses ranging from introductory chemistry to instrumental analysis. Aaron Aponick, Emedio Marchozzi, Cynthia R. Johnston, and Carl T. Wigal. J. Chem. Educ.1998, 75, 465.

Notes on Converting to MicroscaleAntonio Herrera and John AlmySmall glassware is used rather than conventional microscale kits. The equipment and four microscale experiments that emphasize microscale techniques are described. Herrera , Antonio; Almy, John. J. Chem. Educ.1998, 75, 83.

Laboratory Equipment / Apparatus |

Microscale Lab

Educational NMR SoftwarePeter LundbergA description of a compilation of computer programs (EduNMRSoft) suitable for teaching NMR at an introductory to advanced level is presented. Each program is categorized and described by function, hardware requirements, availability, author, and references in the list. Lundberg, Peter. J. Chem. Educ.1997, 74, 1489.

An Exercise To Illustrate the Importance of Sample Preparation in Chemical AnalysisJeffrey G. Dunn, David Philips, and Wilhelm van BronswijkA brief description of the equipment and methods necessary for sample preparation, but concentrates more on the data obtained by students and the conclusions that may be drawn from such data. This exercise may be used by class instructors when introducing students to the pitfalls in sampling and the power of statistics.Dunn, Jeffrey G.; Philips, David; van Bronswijk, Wilhelm. J. Chem. Educ.1997, 74, 1188.

Laboratory Equipment / Apparatus |

Chemometrics

The Remarkable Resilience of Beer's LawMark A. Muyskens and Eric T. SevyDescribed is a case where Beer's law holds to a remarkable degree. Linear absorbance over three orders of magnitude is shown for both pyrazine and 2-methylpyrazine absorption of 266-nm laser light in a 3-m gas cell. This case provides a counter-example for a discussion of deviations from Beer's law. Muyskens, Mark A.; Sevy, Eric T. J. Chem. Educ.1997, 74, 1138.

An Integrated-Circuit Temperature Sensor for Calorimetry and Differential Temperature MeasurementMark MuyskensApplication of an integrated-circuit (IC) temperature sensor which is easy-to-use, inexpensive, rugged, easily computer-interfacable and has good precision is described. The design, based on the National Semiconductor LM35 IC chip, avoids some of the difficulties associated with conventional sensors (thermocouples, thermistors, and platinum resistance thermometers) and a previously described IC sensor. Muyskens, Mark. J. Chem. Educ.1997, 74, 850.

Demonstration of Characteristics of Basic Components of a SpectrophotometerJuwadee ShiowatanaIntroductory experiments were designed to demonstrate the characteristics of basic components of a spectrophotometer using an IL AA/AE spectrophotometer. Emissive properties of various types of radiation source; resolving power of wavelength selectors and response of photodetectors were investigated through simple experiments. Shiowatana, Juwadee. J. Chem. Educ.1997, 74, 730.

Instrumental Methods |

Spectroscopy

An Innovative Design of a Small ReactorP. A. ThomasDesign of a small-volume glass reactor which affords effective gas bubbling simultaneously with mechanical stirring is described. Innovative modification and incorporation of an ordinary hypodermic glass syringe in the design make the fabrication very simple and inexpensive. Thomas, P. A. J. Chem. Educ.1997, 74, 440.

Screening and Sequential Experimentation: Simulations and Flame Atomic Absorption Spectrometry ExperimentsRichard J. StolzbergStudents are introduced to screening and sequential experimentation using simulations and experimentation. The work begins with spreadsheet simulations and practice with the experimental design software. Students learn how to use the graphical output, normal quantile plots, to recognize the specific factors that affect the result of an experiment. In the laboratory, students make a preliminary investigation of the effect of six variables (flame observation height, flame stoichiometry, acetic acid, lamp current, wavelength, and slit width) on the atomic absorption signal for silver.Stolzberg, Richard. J. Chem. Educ.1997, 74, 216.

Integration of National Instruments' LabVIEW Software into the Chemistry CurriculumSteven M. DrewThe overall aim of this continuing project has been to provide students with user-friendly analytical tools that will improve their ability to quickly perform chemical analyses, in turn leaving more laboratory time for experimental design and open-ended investigation. We have found that LabVIEW can be used as a central laboratory software system that can be customized by the instructor to fit specific experimental needs and programmed by students with minimal training.Drew, Steven M. J. Chem. Educ.1996, 73, 1107.

Laboratory Equipment / Apparatus |

Instrumental Methods |

Laboratory Computing / Interfacing

Teaching Analytical Instrument Design with LabVIEWRudy GostowskiThis curriculum was devised to provide hands-on experience with the theory and design of modern instruments. A background in electronics is considered fundamental to this goal. This course extensively utilizes LabVIEW to economically provide basic electronic instrumentation and to serve in data acquisition and manipulation for a student design project.Gostowski, Rudy. J. Chem. Educ.1996, 73, 1103.

Development of a Low-Cost Four-Color LED PhotometerJay R. Hamilton, Jeffrey S. White, Mary B. NakhlehThis photometer resembles a Spectronic 20 in that it detects absorbance at selected wavelengths of visible light. However, the photometer retains the advantages of a dual-beam system. The cost is reduced by the elimination of all optical components, which are often the most expensive portion of spectrophotometers. Hamilton, Jay R.; White, Jeffrey S.; Nakhleh, Mary B. J. Chem. Educ.1996, 73, 1052.

Instrumental Methods |

Laboratory Equipment / Apparatus |

Spectroscopy

An Improved Container for Solutions of Yellow PhosphorousStephen W. WrightThis short article suggests the use of the Sure/Pac cylinder system as an alternative to glass stoppered bottles for the storage of solutions of yellow phosphorous in carbon dioxide.Wright, Stephen W. J. Chem. Educ.1996, 73, 818.

Laboratory Equipment / Apparatus

Making an Inexpensive Tesla Coil from a Car CoilMichael R. Hall and Rubin BattinoDirections are given for making an inexpensive tesla coil from a car coil, along with the suggested uses for the tesla coil. Hall, Michael R.; Battino, Rubin. J. Chem. Educ.1996, 73, 817.

Laboratory Equipment / Apparatus

Simple NMR ImagingPer-Ola QuistRecently we modernized an NMR course for undergraduate chemists. The aim of the new course is to introduce them to the most common applications of NMR.Quist, Per-Ola. J. Chem. Educ.1996, 73, 751.

NMR Spectroscopy |

Instrumental Methods

An Integrated Curriculum for First- and Second-Year Chemistry CoursesT. R. Rettich, David N. Bailey, Forrest J. Frank, and Jeffrey A. FrickKey features of this innovation are the integration of organic and inorganic chemical concepts throughout the first two years of the curriculum, the incorporation of modern instrumentation into lecture and laboratory beginning the first semester, and the matching of topic development to student ability throughout the two-year sequence.T. R. Rettich, David N. Bailey, Forrest J. Frank, and Jeffrey A. Frick. J. Chem. Educ.1996, 73, 638.

Are They Really Sloppy?: A Comparative Analysis of Student Performance in the LaboratoryKatalin Kovács-Hadady and István FábiánThe performance of the students in the analytical laboratory was tested in a potentiometric determination of fluoride ion in anti-caries dental tablets. The analytical results determined by freshman students and experienced personnel were compared. Kovács-Hadady, Katalin; Fábián, István. J. Chem. Educ.1996, 73, 461.

Luminescence Decay and Flash Photolysis Experiments Using an Inexpensive, Laser-Based ApparatusBenjamin A. DeGraff and David A. HornerA low cost, easily assembled apparatus has been developed that allows a number of the most exciting laser-based experiments to be performed for less than eight thousand dollars. Also, presented are a number of experiments which can be done using the apparatus and suggestions for a number of additional ones.DeGraff, Benjamin A.; Horner, David A. J. Chem. Educ.1996, 73, 279.

A Solenoid-Operated Gas or Liquid SaverMichael N. QuigleyA previous note in this Journal described the installation of a water reservoir that greatly facilitates the unattended operation of atomic absorption, emission, and plasma spectrophotometers. A further refinement is detailed here, that relates to the closure of gas valves supplying plasma spectrophotometers in particular, although chromatographs can be similarly modified. Quigley, Michael N. J. Chem. Educ.1996, 73, 194.

Laboratory Equipment / Apparatus |

Spectroscopy |

Laboratory Management

An Easy-to-Build Rotational Viscometer with Digital ReadoutTurgay Seckin and Suphi M. KormalyLow-cost rotational viscometer with digital readout that was well-suited for measuring viscosity was constructed with two dc motors, a rotor, a measuring cup, and milivolt recorder. This rotational viscometer can be used for quick, unsophisticated tests and comparative measurement. Seckin, Turgay; Kormaly, Suphi M. J. Chem. Educ.1996, 73, 193.

Laboratory Equipment / Apparatus |

Physical Properties

A Paper Vernier Scale for Various Laboratory EquipmentsB. S. LarkFabrication and use of a paper vernier scale for a buret is described in this article. Use of this vernier scale makes the reading of the level lying between the graduation marks up to 0.01 mL and thus increases the efficiency of the use of a buret and other similar stem calibrated instruments. Lark, B. S. J. Chem. Educ.1996, 73, 177.

Phase diagrams for aqueous systemsTreptow, Richard S.Review of basic principles involving a phase diagram for an aqueous system and subsequent discussion of how diagrams for specific systems can be used both in the laboratory and for practical applications.Treptow, Richard S. J. Chem. Educ.1993, 70, 616.

Practical adaptor for heating mantlesMarin-Puga, Gustavo; Svoronos, ParisSince most current undergraduate organic labs use both micro and macro scale experiments, the availability of different size heating mantles become necessary. This article suggests a way around the potential problems, especially among third world countries where heating mantles are expensive.Marin-Puga, Gustavo; Svoronos, Paris J. Chem. Educ.1993, 70, 428.

An inexpensive parallel interface to a digital pH meter McMahon, John J.; Braca, Paul R.The authors have designed an experiment in which the students build their own parallel interface "card" from inexpensive components.McMahon, John J.; Braca, Paul R. J. Chem. Educ.1992, 69, A156.

Simple generation of C60 (Buckminsterfullerene).Iacoe, David A.; Potter, William T.; Teeters, Dale.A simple means for the production of fullerene-enhanced graphitic soot using equipment commonly found in most undergraduate chemistry and physics laboratories.Iacoe, David A.; Potter, William T.; Teeters, Dale. J. Chem. Educ.1992, 69, 663.

Synthesis |

Laboratory Equipment / Apparatus |

Alkenes

Modelling a thermostated water bath with a spreadsheetSundheim, Benson R.140. Using a computer model and spreadsheet to analyze the role of relevant parameters (heater, cooling coils, stirrer, sensors, and other objects) on a water bath. Sundheim, Benson R. J. Chem. Educ.1992, 69, 650.

Spreadsheet exercises for instrumental analysisPrais, Michael G.138. Five spreadsheet assignments used in a course on instrument analysis to familiarize students with personal computers and the numerical analysis of data.Prais, Michael G. J. Chem. Educ.1992, 69, 488.

Instrumental Methods |

Chemometrics

A simple generator for common gases at atmospheric pressureElsworth, John F.The current high cost of either a Kipps generator for producing hydrogen sulfide in the undergraduate laboratory, or of the bottled gas, led the writer to construct a simple, economical and efficient generator for use in a laboratory fitted with an efficient fume hood.Elsworth, John F. J. Chem. Educ.1992, 69, 419.

HPLC: A Practical Technique for Future ChemistsHPLC has been particularly helpful in separating the large molecules dealt with in biochemistry, and, therefore, it is essential that future chemists know how to use this technique routinely.J. Chem. Educ.1992, 69, 260.

Raman spectroscopy for the undergraduate physical and analytical laboratoriesGalloway, Douglas B.; Ciolkowski, Edward L.; Dallinger, Richard F.The goals of this paper are to describe the assembly of a simple Raman spectrometer that uses a nitrogen laser and other commonly available or easily purchasable components and to discuss the ways that this instrument can be used to enhance the educational experience in undergraduate physical and analytical chemistry laboratories.Galloway, Douglas B.; Ciolkowski, Edward L.; Dallinger, Richard F. J. Chem. Educ.1992, 69, 79.

The use and utility of phase scienceLaughlin, Robert G.Phase diagrams describe the phase behavior, for a particular system of mixtures spanning a particular range of system variables. One must know how to read and interpret phase diagrams in order to extract and use the information they contain.Laughlin, Robert G. J. Chem. Educ.1992, 69, 26.

An evaluation of drop counting as a volume measurement Ealy, James; Pickering, MilesDrop counting as a volume measurement has gained popularity, especially in high school laboratories. These authors investigate the technique. Ealy, James; Pickering, Miles J. Chem. Educ.1991, 68, A120.

Undergraduate organic and polymer lab experiments that exemplify structure determination by NMRViswanathan, T.; Watson, F.; Yang, D. T. C.Where in the curriculum is the best place to teach experimental NMR methods that are so essential to chemists and chemistry? These authors are of the opinion that NMR must be given more than a cursory introduction involving a single experiment, and present a series of experiments.Viswanathan, T.; Watson, F.; Yang, D. T. C. J. Chem. Educ.1991, 68, 685.

A sonar detector for gas chromatographsYarnitzky, Chaim N.Construction of a sonar detector that operates on measuring the velocity of sound in the analyzed gas.Yarnitzky, Chaim N. J. Chem. Educ.1990, 67, 712.

A convenient method for preparing chromatography columnsWright, Stephen W.; Wright, Ann S.The authors have found that the usual design of flash chromatography pressure regulators allows them to be used as very convenient aids for the rapid filling of columns for Silica Gel chromatography.Wright, Stephen W.; Wright, Ann S. J. Chem. Educ.1990, 67, 517.

Chromatography |

Laboratory Equipment / Apparatus

Recovering silica gel using a Soxlet extractorMittelstadt, Friedrich G.; Franco, Cesar V.In order to keep the cost of the isolation procedures as inexpensive as possible, the Silica Gel used in the process was recovered by means of a Soxlet extractor.Mittelstadt, Friedrich G.; Franco, Cesar V. J. Chem. Educ.1990, 67, 511.

Distillation and the Macintosh: PT Nomograph, an "in-lab" utilitySimon, R.; Senecal, T.115. Bits and pieces, 44. This program duplicates the generic pressure-temperature nomograph, found in a variety of sources, for the detection of the boiling point of a liquid under reduced pressure.Simon, R.; Senecal, T. J. Chem. Educ.1990, 67, 505.

Phases / Phase Transitions / Diagrams |

Physical Properties |

Liquids

A discourse on the drinking birdVemulapalli, G. K.The aims of this article are to describe the operation of the drinking bird in quantitative terms, and to show the similarities between heat engines and the bird.Vemulapalli, G. K. J. Chem. Educ.1990, 67, 457.

"Melting points are uncorrected": True or false?Tiers, George V. D.The classical capillary melting-point determination providing a simple measurement of an unpredictable characteristic property of solid organic compounds, together with a good indication of purity, has been of central importance to the development of organic chemistry.Tiers, George V. D. J. Chem. Educ.1990, 67, 258.

Design of a microscale sublimator Winston, AnthonySublimation is particularly useful when unfavorable solubility properties may lead to high losses of material during crystallization.Winston, Anthony J. Chem. Educ.1990, 67, 162.

The direct relation between altitude and boiling pointEarl, Boyd L.Since the physical parameter whose variation is responsible for the change in boiling point due to altitude is atmospheric pressure, one must make the connection between boiling point and altitude via the pressure, which is directly connected to both.Earl, Boyd L. J. Chem. Educ.1990, 67, 45.

Thermodynamics |

Phases / Phase Transitions / Diagrams |

Physical Properties |

Water / Water Chemistry

On-the-job evaluation of education in analytical chemistryHarwood, John J.Results of a survey in which analytical laboratory supervisors were asked to list the three instrumental and three "wet" chemical or physical analyses most commonly performed in his or her laboratory.Harwood, John J. J. Chem. Educ.1989, 66, A268.

Shine some light on entropy of mixingBrady, K. T.The apparatus described is relatively easy to construct and is quite useful in providing a visual demonstration of the concept of entropy of mixing and diffusion.Brady, K. T. J. Chem. Educ.1989, 66, 339.

A microscale immersion well for photochemical reactionsPenn, John H.; Orr, Richard D.In this document, the authors report the development of a microscale photochemical immersion well that incorporates all of the traditional advantages of microscale glassware, as well as offers significant developments for the pedagogy of organic photochemsitry.Penn, John H.; Orr, Richard D. J. Chem. Educ.1989, 66, 86.

A step-by-step picture of pulsed (time domain) NMRSchwartz, Leslie J.The goal of this paper is to describe a pulsed NMR experiment that is as simple and pictorial as possible, but that stops short of dangerous generalizations and oversimplifications that can lead to contradictions.Schwartz, Leslie J. J. Chem. Educ.1988, 65, 752.

Laboratory applications of the vortex tubeBruno, Thomas J.A brief explanation of the function of the vortex tube and some heating and cooling applications for the chemistry laboratory.Bruno, Thomas J. J. Chem. Educ.1987, 64, 987.

A controller of level of liquidsAlzabet, H. R.; Barbero, J. A.A device that is capable of controlling liquid level and can be used with any conducting liquid.Alzabet, H. R.; Barbero, J. A. J. Chem. Educ.1987, 64, 727.

An introductory quantitative GC experiment for the organic chemistry laboratoryLeber, Phyllis. A.GC instrumentation is complicated enough that students need introductory exposure to the technique before embarking on its applications. The authors accomplish this by developing an introductory GC experiment that allows students to explore the scope and limits of the technique.Leber, Phyllis. A. J. Chem. Educ.1986, 63, 550.

Instrumentation and the total analytical processPleva, Michael A.; Settle, Frank A., Jr.Emphasizing the total analytical process by considering the goal of the analysis, isolation of the system on which the analysis is to be performed, physical and chemical manipulations of the sample to produce the analyte, measurement of the analyte, and evaluation of the results, in addition to instrumental techniques.Pleva, Michael A.; Settle, Frank A., Jr. J. Chem. Educ.1985, 62, A85.

A problem in calibrating a spectrophotometerJohnson, James G.Standardization checks should be carried out under exactly the same conditions as used for daily work with the instrument.Johnson, James G. J. Chem. Educ.1985, 62, 885.

Quantitative analysis of a mixture by NMR spectroscopyWallace, TimAdding a measured quantity of an inert, easily removed reference compound with a simple NMR signal that does not overlap with the mixture's signal can provide the basis for an instructive experiment.Wallace, Tim J. Chem. Educ.1984, 61, 1074.

A simple device for flash chromatographyFeigenbaum, A.Device that eliminates the problems introduced by the requirement to use compressed air with flash chromatography.Feigenbaum, A. J. Chem. Educ.1984, 61, 649.

Modification of a microwave oven for laboratory useAndrews, Judith; Atkinson, George F.Modifying a microwave oven to protect it against energy buildup when samples are dried by using a small water ballast.Andrews, Judith; Atkinson, George F. J. Chem. Educ.1984, 61, 177.

Two readily-constructed instruments for the teaching laboratoryIsaacs, Neil S.The authors report designs for a colorimeter and for a polarimeter; both of which may be constructed readily with average workshop facilities and whose performance is superior to many commercial instruments commonly in use in teaching laboratories.Isaacs, Neil S. J. Chem. Educ.1983, 60, 607.

Quantitative Analysis |

Laboratory Equipment / Apparatus

Molecular association and structure of hydrogen peroxideGigure, Paul A.The typical textbook treatment of molecular association and structure of hydrogen peroxide, and the implications of these concepts for the physical properties of hydrogen peroxide tend to be oversimplified and inaccurate.Gigure, Paul A. J. Chem. Educ.1983, 60, 399.

Molecular Properties / Structure |

Physical Properties |

Phases / Phase Transitions / Diagrams |

Hydrogen Bonding

An effective demonstration of some properties of real vaporsMetsger, D. ScottThe apparatus described in this article has been found by the authors to be the most effective in vividly illustrating the behavior of a nearly ideal gas to first year chemistry students.Metsger, D. Scott J. Chem. Educ.1983, 60, 67.

Calculator program for analysis of a complex by Job's methodHouse, J. E., Jr.25. Bits and pieces, 9. Program permits users to measure an appropriate property of a complex as a function of composition of the solutions and determine the composition of the complex according to Job's method.House, J. E., Jr. J. Chem. Educ.1982, 59, 132.

Phase transfer catalysis. Part II: Synthetic applicationsGokel, George W.; Weber, William P.In this month's continuation of an article, the authors have catalogued a number of illustrative examples so that the range of applicability of phase transfer catalysis will be.Gokel, George W.; Weber, William P. J. Chem. Educ.1978, 55, 429.

A sample preparation technique for column chromatographyBeller, Nicholas R.; Hilleary, Christopher J.The authors have found a simple and effective method of sample preparation for use in column chromatography which resembles the application of a sample to a thin layer chromatography plate, where the solid sample in solution is absorbed by the solid phase as the solvent evaporates.Beller, Nicholas R.; Hilleary, Christopher J. J. Chem. Educ.1976, 53, 498.

Thin Layer Chromatography |

Solutions / Solvents |

Phases / Phase Transitions / Diagrams |

Solid State Chemistry

Photooxidation of methionine. An integrated organic-analytical-biochemistry laboratory experimentLewis, Catherine; Scouten, William H.The experiments presented here familiarize the student with the organic reactions necessary to prepare the starting material; introduces the use of glass beads for immobilizing a catalyst; demonstrates the use of light and methylene blue as oxidizers; requires the implementation of an important analytical technique, thin layer chromatography; provides the student with a good example of the reactivity of one amino acid, methionine.Lewis, Catherine; Scouten, William H. J. Chem. Educ.1976, 53, 395.

Computer-controlled colorimetryPater, F. G.; Perone, S. P.In order to illustrate more fully the capabilities of the computer for experimental control, a computer-controlled colorimeter has been conceived, where the computer can select the wavelength of light passing through the sample as well as execute data acquisition and data processing functions.Pater, F. G.; Perone, S. P. J. Chem. Educ.1973, 50, 428.

Physical chemistry of the drinking duckPlumb, Robert C.; Wagner, Robert E.The operation of the drinking bird is easily understood in terms of a few elementary physical chemistry principles.Plumb, Robert C.; Wagner, Robert E. J. Chem. Educ.1973, 50, 213.

Comparison of analytical methodsBeilby, Alvin L.One important aspect of the education in analytical chemistry of chemists and others using analytical methods should be the continued emphasis on the comparison of analytical methods so students can learn to chose intelligently the proper analytical methods for the solution of chemical problems.Beilby, Alvin L. J. Chem. Educ.1972, 49, 679.

Instrumental Methods

Thermal, flow, and coolant level switchDavies, T. K.; Hodapp, H.Design for a switch that can be used for most coolant flow and over-heating problems.Davies, T. K.; Hodapp, H. J. Chem. Educ.1972, 49, 443.

Controlled evaporation with an extended hotplate topAtkinson, George F.; Curtis, K. E.A device that enables the evaporation of sample solutions to a small volume with a greatly reduced risk of baking them dry.Atkinson, George F.; Curtis, K. E. J. Chem. Educ.1972, 49, 108.

Evaporative cooling condenserGoldberg, Stanley I.; Bailey, William D.Design for a condenser that operates on the principle of evaporative cooling through the use of compressed air and is constructed from ordinary laboratory condensers.Goldberg, Stanley I.; Bailey, William D. J. Chem. Educ.1970, 47, 783.

A thermocouple reference bath with long term stabilityBraunstein, Jerry; Ray, RidleyPlacing a Dewar in an ice chest filled with ice is found to maintain a nearly constant reference, ice-water mixture temperature within the Dewar for six months.Braunstein, Jerry; Ray, Ridley J. Chem. Educ.1970, 47, 611.

Nmr analysis of water-acetic acid solutionsBrabson, G. DanaPresents an experiment intended to teach the operation of NMR instrumentation and the interpretation of the data it collects, as well as demonstrate a significant principle of chemistry.Brabson, G. Dana J. Chem. Educ.1969, 46, 754.

NMR Spectroscopy |

Aqueous Solution Chemistry |

Instrumental Methods

Purification of low-melting compoundsKaye, Irving AllanPresents a procedure that addresses difficulties to purification by recrystallization caused by the tendency of some low-melting compounds to precipitate from solution as oils.Kaye, Irving Allan J. Chem. Educ.1969, 46, 696.

Analytical chemistry for honors applied chemistry studentsAtkinson, G. F.This paper outlines the analytical chemistry content of a new program being introduced at the University of Waterloo (Ontario, Canada) and discusses some of the rationale underlying the development.Atkinson, G. F. J. Chem. Educ.1969, 46, 519.

An instrument for source intensity compensation in atomic fluorescenceO'Haver, T. C.; Winefordner, J. D.The purpose of this paper is to describe an instrumental system that compensates for variations in the source intensity, thus allowing the use of unstable electrodeless discharge lamps as sources of excitation in atomic flame spectrometry.O'Haver, T. C.; Winefordner, J. D. J. Chem. Educ.1969, 46, 435.

Instrumental Methods |

Spectroscopy |

Atomic Spectroscopy

Integrated circuits in the instrumental laboratoryScherer, George A.A brief introduction to integrated circuits that exemplifies their use in instrumentation through the construction of a square wave generator, audio amplifier, decimal counting unit, and operational amplifier.Scherer, George A. J. Chem. Educ.1969, 46, 399.

Laboratory Equipment / Apparatus |

Instrumental Methods |

Semiconductors

Apparatus for electrodeposition experimentsAtkinson, G. F.; Shaw, John H.Presents an alternative to commercial instruments for the electrodeposition of copper and lead from brass samples.Atkinson, G. F.; Shaw, John H. J. Chem. Educ.1969, 46, 387.

A convenient glass-to-glass connectorCollins, Kenneth E.Describes two modifications of a glass-to-glass O-ring coupling design that can be made easily and cheaply by a glassworker.Collins, Kenneth E. J. Chem. Educ.1969, 46, 179.

A simple and accurate dilatometer for liquidsWagner, Robert E.; Meyer, Edwin F.The density of a liquid as a function of temperature may be readily measured using this dilatometer.Wagner, Robert E.; Meyer, Edwin F. J. Chem. Educ.1968, 45, 349.

The identification of vegetable oils: A gas chromatographic experimentCover, Richard E.In this procedure the student is given a sample of oil which he saponifies and then esterfies to form the methyl esters of the fatty acids; the esters are then extracted, concentrated, and identified through gas chromatography.Cover, Richard E. J. Chem. Educ.1968, 45, 120.

A modified micro-boiling-point techniqueBulbenko, George F.A short note regarding the use of a commercial melting point tube as a fine capillary bubbler for micro-boiling-point determination.Bulbenko, George F. J. Chem. Educ.1968, 45, 43.

The rest point of the balanceHakala, Reino W.Elaborates on the formula for finding the rest point of a balance.Hakala, Reino W. J. Chem. Educ.1967, 44, 306.

Laboratory Equipment / Apparatus

Liquid-liquid extractionJoseph-Nathan, P.Describes how liquid-liquid extraction can be done using commercially available substances and an apparatus of small dimensions that still allows an experiment to be followed visually.Joseph-Nathan, P. J. Chem. Educ.1967, 44, 176.

Separation Science |

Liquids |

Laboratory Equipment / Apparatus

A new short-path distillation apparatusMorrison, HarryThis design is basically a modification of the kugelrohr method but was created to surmount difficulties in cooling the receiver and removing the distillant.Morrison, Harry J. Chem. Educ.1967, 44, 161.

Application of binary and ternary arithmetic to weighing problemsLang, Sidney B.; Peck, Robert L.The purpose of this paper is to illustrate some of the advantages of using a ternary system of weights on a two-pan balance and a binary system on a single-pan balance.Lang, Sidney B.; Peck, Robert L. J. Chem. Educ.1967, 44, 48.

Improvements in the Victor-MeyerBader, MorrisTwo improvements in the Victor-Meyer have simplified the apparatus and greatly increased the accuracy of molecular weight determinations.Bader, Morris J. Chem. Educ.1966, 43, 500.

Coulometry: A series experimentVan Lente, K. A.In this experiment Faraday's Laws are applied to three coulometers - a silver coulometer, an iodine coulometer, and a gas coulometer - all connected in series.Van Lente, K. A. J. Chem. Educ.1966, 43, 306.

Electrochemistry |

Laboratory Equipment / Apparatus

A broad-surface condenserSchultz, Harry P.Describes a light, broad-surface condenser made from two Pyrex watch glasses whose edges have been sealed to one another with epoxy.Schultz, Harry P. J. Chem. Educ.1966, 43, 272.

Versatile magnetic stirrer and flexible couplerWarkentin, J.Describes a versatile magnetic stirrer and flexible coupler connected to a vacuum line that can be used to determine reaction rates by monitoring gas volume as a function of time.Warkentin, J. J. Chem. Educ.1966, 43, 265.

Demonstration of the glass transitionKoleske, Joseph V.; Faucher, Joseph A.Glucose pentaacetate (GPA) has been found to be an excellent compound to use for a simple demonstration of the glass-rubber and amorphous-crystalline transitions.Koleske, Joseph V.; Faucher, Joseph A. J. Chem. Educ.1966, 43, 254.

Use of polychromatic radiation in absorption photometryStrong, Frederick C., IIIProportionality between concentration and absorbance (Beer's Law) requires approximately monochromatic radiation to the extent that the variation of absorptivities with wavelength results in less error than other instrumental and chemical errors.Strong, Frederick C., III J. Chem. Educ.1965, 42, 342.

Instrumental Methods |

Spectroscopy

Three dimensional models in phase rule studiesPetrucci, Ralph H.Describes the results of a NSF program to illustrate and encourage the use of three-dimensional representations in the teaching of phase rule principles.Petrucci, Ralph H. J. Chem. Educ.1965, 42, 323.

A modified condensing apparatus for both refluxing and distillingGoddard, Charles; Henry, Malcolm C.The condenser described here can be pivoted from a vertical position (refluxing) to one approximately horizontal (distilling) without having to switch the inlet and outlet condensor connections.Goddard, Charles; Henry, Malcolm C. J. Chem. Educ.1965, 42, 221.

Modular instrumentation in analytical chemistryEwing, Galen W.It is the purpose of this paper to describe an approach to modular instrumentation in analytical chemistry in which students complete the assembly of partially assembled instruments.Ewing, Galen W. J. Chem. Educ.1965, 42, 32.

Method for the determination of liquid-vapor binary equilibriaColgate, S. O.; Hanrahan, R. J.In the method described here, which is a modification of the refluxing procedure, provision is made for collecting samples of both condensed vapor and liquid without disturbing the equilibrium.Colgate, S. O.; Hanrahan, R. J. J. Chem. Educ.1964, 41, 433.

The history of the Warburg apparatus: Some reminiscences on its useOesper, PeterThe Warburg apparatus is a device for measuring the pressure of a gas at constant volume and constant temperature so that the pressure is a measure of the quantity of gas and changes in pressure reflect the production or absorption of gas.Oesper, Peter J. Chem. Educ.1964, 41, 294.

Laboratory Equipment / Apparatus |

Gases

A versatile and inexpensive controlled potential polarographic analyzerEnke, C. G.; Baxter, R. A.The instrument described in this article was built to be used for basic research in nonaqueous and ac polarography and for instruction in polarographic principles and techniques in introductory and advanced analytical chemistry laboratories.Enke, C. G.; Baxter, R. A. J. Chem. Educ.1964, 41, 202.

An inexpensive spectrograph of moderately high resolutionSchoenbeck, Ralph; Tabbutt, Frederick D.This article describes a spectrograph with a resolving power greater than 6000 that can easily be built for a minimal cost.Schoenbeck, Ralph; Tabbutt, Frederick D. J. Chem. Educ.1963, 40, 452.

A funnel for the controlled addition of solidsBloomfield, Jordan J.; Nunamaker, HarryDescribes an addition funnel for solids based on the use of a Teflon screw to deliver solids at any desired rate to a reaction.Bloomfield, Jordan J.; Nunamaker, Harry J. Chem. Educ.1962, 39, 255.

Chomatographic EquipmentLewin, S. Z.Examines the following topics: selectivity in the distribution of components between two phases, chromatographic development, types of chromatographic systems, the production of counter-current flow, the scale of chromatographic separations, the components of chromatographs, the two-phase system, and containers.Lewin, S. Z. J. Chem. Educ.1961, 38, A515.

A demonstration polarimeterSpear, Carleton S.Describes the construction of a simple polarimeter that can be constructed by students for use in laboratory experiments.Spear, Carleton S. J. Chem. Educ.1960, 37, 203.

Vessel for small-scale reactionsKasman, SidneyThis brief note describes a modified test tube that allows a thermometer to be used to measure temperature changes involved in the reaction of very small amounts of material.Kasman, Sidney J. Chem. Educ.1960, 37, 150.

Glass rod as a stirrer in pH titrationsVenkatachalam, K. A.This short note describes how a glass rod can be used as a stirrer in potentiometric titrations without interfering with the glass electrode.Venkatachalam, K. A. J. Chem. Educ.1959, 36, 301.

Laboratory Equipment / Apparatus |

Titration / Volumetric Analysis

Letters to the editorGuenther, William B.The author questions the continued use of two pan balances in the quantitative analysis course.Guenther, William B. J. Chem. Educ.1959, 36, 257.

A simple differential fermentographBorzani, Walter; Vairo, Marina L. R.The very simple differential fermentograph described in this report can give good comparative measures of the influence of several factors on the fermentation rate when gases are produced.Borzani, Walter; Vairo, Marina L. R. J. Chem. Educ.1959, 36, 242.

Laboratory Equipment / Apparatus |

Gases

Balance instruction by televisionHayes, John R.; Schempf, John M.; Murnin, Joseph A.Describes the authors' experience in using closed circuit television to teach students in quantitative analysis the technique of weighing with the analytical balance.Hayes, John R.; Schempf, John M.; Murnin, Joseph A. J. Chem. Educ.1958, 35, 615.

A new addition apparatusScheer, Irving; D'Adamo, Amedeo F., Jr.This device helps to ease the addition of a solid reagent in small portions to a reaction mixture, particularly reagents that are sensitive to air and moisture.Scheer, Irving; D'Adamo, Amedeo F., Jr. J. Chem. Educ.1958, 35, 281.

Laboratory Equipment / Apparatus

Nomenclature of phase transitionMcDonald, James E.Discusses the curious situation in which the terminology of chemistry and physics has only five words to describe the six possible transitions between three states of matter.McDonald, James E. J. Chem. Educ.1958, 35, 205.

A portable mixture colorimeter of high absolute accuracyMowery, Dwight F., Jr.The equipment described is designed to provide a more rapid and uniform mixing of solutions, allows the use of equal volumes, and requires only one Beckman thermometer.Mowery, Dwight F., Jr. J. Chem. Educ.1957, 34, 244.

Laboratory Equipment / Apparatus |

Instrumental Methods |

Calorimetry / Thermochemistry

An automatic titratorPhillips, John P.Describes the design and operation of a photoelectric automatic titrator suitable for demonstrations in elementary quantitative analysis.Phillips, John P. J. Chem. Educ.1957, 34, 203.

A technique for vacuum filtrationBrown, James R.The method described here permits one to filter with suction directly into a variety of receivers, thus avoiding the need to transfer from a suction flask or to rinse down a filtering adapter.Brown, James R. J. Chem. Educ.1957, 34, 165.

Lecture thermometer and voltmeterDutton, Frederic B.A sensitive temperature-indicating device with a reasonable rapid response time that relies on a thermocouple and can be seen by a large group.Dutton, Frederic B. J. Chem. Educ.1955, 32, 478.

A simple, automatic gas buretGoodwin, Robert D.Presents a simple buret that automatically makes adjustments to preserve a constant pressure in the system under study.Goodwin, Robert D. J. Chem. Educ.1954, 31, 369.

A taper-tube condenserFeldkamp, Rolland F.; Wilt, William A.In an attempt to improve the drainage and increase the efficiency of a small, Liebig-type condenser, the authors have designed and built a taper-tube condenser.Feldkamp, Rolland F.; Wilt, William A. J. Chem. Educ.1954, 31, 84.

An interferometerMalik, Jim G.; Speirs, John L.; Rogers, Max T.Presents the general theory of interferometery, its uses, and a description of a constructed instrument and its operation.Malik, Jim G.; Speirs, John L.; Rogers, Max T. J. Chem. Educ.1953, 30, 437.

Laboratory Equipment / Apparatus |

Instrumental Methods

A visual demonstration of fractional distillationOsburn, James O.Describes the design of a glass bubble-cap column, a glass-packed column, and an equilibrium diagram for an engineering department open-house.Osburn, James O. J. Chem. Educ.1953, 30, 412.

An electronic interval markerMarion, Alexander P.The device described here provides a tone impulse at a rate variable from 30 to 120 per minute and an additional characteristic signal for submultiples within a range of 5 to 15 per minute.Marion, Alexander P. J. Chem. Educ.1953, 30, 252.

Laboratory Equipment / Apparatus |

Kinetics

Some uses of radio service kits in teaching quantitative analysisPhillips, John P.The problem of obtaining inexpensive and practical instruments to supplement conventional equipment specifically designed for chemical purposes has been partially solved by the purchase of radio service instrument kits.Phillips, John P. J. Chem. Educ.1953, 30, 70.

Quantitative Analysis |

Laboratory Equipment / Apparatus |

Instrumental Methods

The kinetic structure of gasesSlabaugh, W. H.Describes a model that illustrates the kinetic properties of gases and ii use to demonstrate the effect of temperature changes on the motion of gas particles.Slabaugh, W. H. J. Chem. Educ.1953, 30, 68.

An inexpensive thermostatLinke, William F.A simple and surprisingly efficient thermostat can be constructed in minutes using a three-necked flask and a liquid (or mixture of liquids) that boils at a desired temperature.Linke, William F. J. Chem. Educ.1952, 29, 492.

Laboratory Equipment / Apparatus

Instructional error in quantitative analysisBlaedel, W. J.; Jefferson, J. H.; Knight, H. T.Instructional error is that which is beyond the control of students in making quantitative analyses; illustrates this in the determination of chloride as silver chloride.Blaedel, W. J.; Jefferson, J. H.; Knight, H. T. J. Chem. Educ.1952, 29, 480.

Quantitative Analysis |

Instrumental Methods

A new and useful laboratory clampGrantom, Roy L.Describes a clamp that holds a rubber stopper in place to allow the maintenance of a moderate pressure in a straight-wall glass tube.Grantom, Roy L. J. Chem. Educ.1952, 29, 455.

Laboratory Equipment / Apparatus

A recorder for polarographyThomas, E. B.; Nook, R. J.The switching arrangement and potential recorder presented here has been used primarily for polarographic work, but may be adapted to many other uses that employ small changes of potential or current to measure or control chemical processes.Thomas, E. B.; Nook, R. J. J. Chem. Educ.1952, 29, 414.

Laboratory Equipment / Apparatus |

Electrochemistry

The 4 in 1 chem-mixerWendland, RayThis device allows one to rely on one- rather then three-necked flasks.Wendland, Ray J. Chem. Educ.1952, 29, 365.

Laboratory Equipment / Apparatus

The thermomatic steamerWendland, RayPresents an apparatus designed to be kept together, ready for immediate use and easy to clean without tearing down, to conduct steam distillations in organic chemistry.Wendland, Ray J. Chem. Educ.1952, 29, 364.

A constant-temperature bath for warm climatesLoveless, W. M.; Marshall, Madison L.Describes a simple water bath with a cooling element that can be moved from one room to the next.Loveless, W. M.; Marshall, Madison L. J. Chem. Educ.1952, 29, 137.

Electrolysis with controlled cathode potentialsFoster, Duncan G.This paper describes the construction of an instrument for the control of a cathode's potential during an electrolysis procedure (a potentiostat) and its use in a quantitative analysis laboratory.Foster, Duncan G. J. Chem. Educ.1951, 28, 626.